As another Penguins training camp opened Thursday, coach Mike Sullivan began the process of sifting through the team’s deepest depth chart in years.

The Penguins had 31 new players on the ice Thursday. They have 13 defensemen who have played in NHL games. Time will tell if they have a quality third line, but they have enough forwards to deploy a solid fourth, fifth and maybe even sixth. Of the seven goalies in camp, four have played in the league.

With so many new faces, we will see the Penguins tinker with certain combinations throughout training camp and into the regular season, especially if a particular line or defensive pair isn’t performing up to expectations. That is part of the reason why the coach gave a disclaimer to reporters after practice.

“I wouldn’t read too much into the line combinations at this point,” he said.

As Sullivan explained, the Penguins are trying to split up their veteran talent and young prospects as equally among the three camp squads as possible to ensure a clean evaluation. And while many roster spots are already set in stone, they want to provide opportunities for someone to surprise in camp.

All that said, Sullivan did concede there is something to some combos.

“We have put together some combinations that we’re intrigued about, that we may go with,” he said, citing a trio of Matt Nieto, Noel Acciari and Jeff Carter.

So which combinations for the start of training camp are nothing, and which ones actually mean something? Let’s sort through a few that we saw Thursday:

Erik Karlsson started out next to Marcus Pettersson, not Ryan Graves

Something. One of the primary points of interest heading into training camp was the structure of the top two defensive pairs. We knew whom the four players would be. It was just a matter of seeing which defensive-minded blue liner Sullivan would pair with Karlsson and whom would team up with Kris Letang.

To ease the transition for the newcomers, it would make sense for Sullivan to pair one of them with an incumbent to start. And Sullivan did just that. Thursday, it was Pettersson who partnered up with Karlsson, his fellow Swede. Graves, who has stylistic similarities to Brian Dumoulin, was alongside Letang.

There could be some tinkering during the next couple of weeks, but given what we have seen from Sullivan in the past, it feels like we can pencil these combinations in for the opening night lineup. After all, Sullivan and his staff have had months to think this decision through. Now, give the players time to jell.

Reilly Smith skated with Evgeni Malkin in his first Penguins practice

Something. Honestly, it would have been very surprising had Smith not been with Malkin, even with Jake Guentzel still sidelined for the onset of camp.

When the Penguins acquired Smith from the Vegas Golden Knights, Sullivan said he felt Smith, who has five 20-goal seasons in the league, would be a good match with Malkin, in part because Smith is a scoring threat off the rush.

Sure enough, Sullivan is giving Smith a shot next to Malkin, with Andreas Johnsson playing right wing on that line Thursday. Smith and Malkin were buzzing throughout Thursday’s practice, getting the better of Sidney Crosby’s squad.

If that continues, there is a strong likelihood Sullivan will keep the two together as a core forward duo and instead worry about the third guy on their line.

Rickard Rakell wasn’t with Crosby nor Malkin, but instead Lars Eller

Nothing. Moving Rakell, Smith or Bryan Rust up and down the lineup is one way for the Penguins to inject some offense into the bottom six. And maybe we actually do see that in games. But let’s not forget Jason Zucker was deployed similarly in last year’s camp and he spent all season on Malkin’s line.

The expectation is Rakell and Rust get flip-flopped on the top two lines again this season, with Sullivan changing that up whenever his team hits a rut.

That said, there was some intrigue with the line Rakell played on Thursday. It had Eller at center and Drew O’Connor at left wing. If O’Connor takes another step in his development, that is actually a trio that makes theoretical sense.

Jeff Carter was moved from center over to right wing to open camp

Something. Carter was overextended last season as the third-line center. He will likely slot into a fourth-line spot in 2023-24 — and slide over to the wing.

Thursday, Carter skated on a bottom-six line with Acciari at center and Nieto at the other wing. Afterward, he said he skated on the right side throughout the informal player skates, presumably at the urging of the coaches.

Carter, 38, downplayed the potential benefits of moving to wing in terms of having a little less wear and tear. But given how gassed he looked at times last year, this is a logical move for the Penguins to make as they try to squeeze a little more quality hockey out of Carter in the last year of his contract.